Simplify the following expression: $y = \dfrac{3a - 7}{4} \div \dfrac{3a}{3}$
Solution: Dividing by an expression is the same as multiplying by its inverse. $y = \dfrac{3a - 7}{4} \times \dfrac{3}{3a}$ When multiplying fractions, we multiply the numerators and the denominators. $y = \dfrac{ (3a - 7) \times 3 } { 4 \times 3a}$ $y = \dfrac{9a - 21}{12a}$ Simplify: $y = \dfrac{3a - 7}{4a}$